Cerebellar hypoplasia and Cohen syndrome: a confirmed association.

摘要

Cohen syndrome (OMIM 216550) is a rare autosomal recessive disorder first described in 1973 [Cohen et al, 1973]. Patients have been identified worldwide but are over represented in the Finnish population. The key clinical features were established through the assessment of a Finnish cohort of 29 patients with a high level of clinical homogeneity and include: (1) mental retardation and microcephaly; (2) typical facial features; (3) neutropenia (neutrophil count <1.5 x 10~9/L); (4) pigmentary retinopathy and myopia; and (5) hypotonia and joint hyperextensibility [Kivitie-Kallio and Norio, 2001]. A subsequent review of 33 non-Finnish patients found that the proposed diagnostic criteria only identified 24% of the patients as having true Cohen syndrome. A consequent revision of the diagnostic guidelines allowing the identification of patients from more heterogeneous populations states that significant learning difficulties are to be observed in conjunction with two of the following clinical features: typical facial gestalt, pigmentary retinopathy, or neutropenia [Chandler et al., 2003].